This invention relates to an imaging device. More specifically the invention is concerned with an imaging fuse attachable to an airborne object, such as a projectile. The invention is also concerned with a system and method making use of such an imaging device.
The term projectile as used herein the specification and claims is used to denote any type of launched/fired object, either self propelled e.g. a rocket, a missile, etc, or a kinetic projectile e.g. a shell, a projectile fired from a gun or canon, a mortar, a high caliber machine gun, etc.
An imaging projectile may be of many configurations and may be launched towards its destination by different means. The projectile may be a self-propelled type in which it is fitted with a rocket or other type of engine and may also comprise remote control or other steering arrangements for guiding the projectile towards its destination. The projectile may alternatively be a kinetic body launched/fired from a gun by a charge, e.g. from a mortar, a gun or a cannon.
The projectile may have apart from its imaging function also other purposes, e.g. it may comprise an explosive charge which is adapted to explode above or at a target or it may comprise an illuminating body which will be expelled from the projectile above the target area for illumination, as known, per se, etc.
An imaging projectile may be used for non-military purposes, e.g. for aeronautic experiments where it is required to examine aeronautic behavior and performances of a body during flight or free fall. Rather than using an air tunnel which requires sophisticated logistics, it is possible to launch the body by a suitable carrying projectile fitted with an imaging assembly which transmits an image to a receiving station during trajectory of the projectile. By analyzing the image obtained at the receiving station one may obtain the required telemetry parameters by monitoring the vibrations, course of flight, etc.
An imaging projectile may also be used for fast obtaining of prompt images of regions which are inaccessible, e.g. for obtaining geological and other information such as damage assessment during an earthquake or volcanic eruptions, during a large scale fire or a flood, etc.
Among the many uses of an imaging projectile, one should mention also its military use as a reconnaissance aid for obtaining an image of a territory at real time and at essentially low cost without complicated logistics.
In general, imaging systems of the concerned type fall into several categories:
Shells with a line array sensor (LAS) wherein a high roll speed of the projectile is used to scan the target area and provide a common two-dimensional image;
A projectile with a stabilizing pin assembly, which pins project during a certain stage of flight in order to stop the roll and thus enable obtaining an image with a regular video camera;
A projectile adapted for disintegrating during trajectory and release an imaging sensor, typically a camera or video camera suspended from a parachute or balloon;
A projectile utilizing a gyroscope system to prevent spin with suitable imaging mechanisms;
A projectile, typically a guided one, wherein a fiber optic line extends behind the projectile towards a pick up station wherein image data is received.
A myriad of publications disclosed imaging projectiles and imaging fuses for different purposes, as well as methods and devices for improving such apparatuses, in particular improving stability of an imaging projectile during its trajectory, improving impact resistance and other launched imaging systems among these are: U.S. Pat. Nos. 3,653,737, 3,721,410, 3,962,537, 4,431,150, 4,438,893, 4,512,537, 4,543,603, 4,561,611, 4,583,703, 4,679,748, 4,917,330, 5,077,465, 5,201,895, 5,379,968, 5,467,681, 5,529,262, 5,669,581. A micro-reconnaissance imaging system has also been disclosed by the Xybion Corporation in their Website at Xybion.com therefor.
However, the above disclosed references involve some technical drawbacks such as, for example, some of the above references are not designed to withstand the high G shock during launching which can range between around 6,0005 G in the case of launching a projectile from a mortar or up to about 80,000 G in some particular cases of firing a projectile from a tank""s gun.
Still another typical problem concerned with projectiles of the concerned type is the significantly high speed of rotation (spin), at times in the order of about 20,000 RPM, which renders the imaging process impossible as the obtained image smears.
Another common problem which occurs with imaging projectiles fitted with imaging fuses is the strong vibrations during trajectory which distort the image and which together with the smeared image owing to spinning of the projectile, yield a useless image.
Even more so, the dimensions of the imaging fuse which may be attached to an imaging projectile are constraint and thus the power supply means and signal transmission components are of restricted dimensions and power. This results in requiring special tracking equipment, either ground or airborne, for tracking the trajectory of the projectile and for picking up and processing an image transmitted from the imaging fuse.
Still another drawback of recognizance and imaging devices is their ability to provide an image at poor conditions such as essentially low cloud bed, dust or smoke.
It is an object of the present invention to provide an improved imaging projectile and an imaging fuse therefor which overcome the above drawbacks. The invention is further concerned with an imaging system making use of an imaging device in accordance with the present invention and further, an imaging method for easily obtaining an image of a remote target area.
According to a first of its aspects, the invention is directed to an imaging fuse comprising a housing fixable within a receptacle at a fore end of a projectile, a coaxial support frame rotatably supported within the housing and fitted with an imaging assembly, said support frame being axially displaceable with respect to the housing; an axial shock absorbing system intermediate the housing and the support frame; and a spin suppressing mechanism associated with the support frame, for suppressing its rotation with respect to the housing.
The invention is further concerned with an imaging projectile fitted at a fore end thereof with an imaging fuse comprising a housing, a coaxial support frame rotatably supported within the housing and fitted with an imaging assembly, said support frame being axially displaceable with respect to the housing; an axial shock absorbing system intermediate the housing and the support frame; and a spin suppressing mechanism associated with the support frame, for suppressing its rotation with respect to the housing.
By still another aspect of the invention there is provided an imaging system comprising:
i) a projectile formed at a fore end (also referred to as a nose tip) thereof with a fuse receptacle;
ii) an imaging fuse in accordance with the invention, fixable to said fuse receptacle;
iii) a launching mechanism for launching the projectile towards a target area;
iv) a tracking system for locating and tracking the trajectory of the projectile; and
v) an image data receiving and image processing unit adapted for picking up image data transmitted from the fuse and processing it into a solved image.
The term solved image as referred to in the specification and claims refers to an image in which particulars of a target area are recognizable and/or to an image of which the geographic ordinates of each pixel are known. However, for obtaining a solved image it is required to obtain a reference image database of the target area.
The invention is further directed to a method for obtaining an image of a target area, the method comprising:
i) launching an imaging projectile fitted with an imaging fuse in accordance with the present invention;
ii) locating the position of the projectile and tracking it along its trajectory; and
iii) receiving image data transmitted from the image fuse and processing it into a solved image.
By one particular embodiment, the invention further suggests that the data receiving and image processing unit further comprises a reference image database and wherein the image received at the image processing unit is compared with the reference image data for identifying location of the projectile and for assessing differences between the reference image and the processed image captured by the projectile.